1. Field of the Invention
This invention relates to pipeline scrapers, usually referred to as pipeline pigs of the type which are placed in a pipeline and moved along by the fluid flow. Pipeline pigs are used for a number of purposes including scraping the interior of a line to remove rust and encrustation, separating one fluid component from another, and when used in pipelines for conveying gas, forcing the removal of water and other liquids which have condensed in the line and settled in low areas.
The present invention is directed towards an improved flexible pipeline pig which has advantages over previously known constructions. The primary advantages are that the pig easily bends around corners or imperfections in a pipeline and is formed of plastic material having the benefits of economy, long life, and freedom from reaction with the fluids found in most pipelines.
2. Description of Prior Art
The use of pipeline pigs is well known in the industry. Pigs have been designed for various applications and uses. Some pipeline pigs include wire brushes for scouring the interior of the lines through which they pass. Others include arrangements wherein portions of the pipeline pig are hinged to each other to allow flexibility. While existing types of pipeline pigs work satisfactorily, a disadvantage in existing designs is that they are either formed of a fixed central shaft and therefore, are inflexible, or, if made to be flexible, include components which are hinged together and thereby substantially increasing the costs or of one piece construction with no re-usable components therefore losing the whole pig when damaged.
An object of the present invention is to provide a pipeline pig which has the advantage of increased flexiblity while at the same time eliminating the requirement of hinged connections between portions of the pig or loss of the entire pig when damaged.
More particularly, an object of this invention is to provide an improved flexible pipeline pig formed substantially all of plastic components which are quickly and easily assembled on a flexible plastic shaft and which thereby achieves economy of manufacture and improved results of use.
These general objects as well as other and more specific objects of the invention will be fulfilled in the following description and claims taken in conjunction with the attached drawings.